It is known to make polyimides by thermal imidization of the intermediate polyamic acid obtained by reaction of a dianhydride (or a corresponding acid-ester or tetracarboxylic acid) and a diamine. Polyimides from the product of reaction of 3,5-diaminobenzotrifluoride and dianhydrides (or corresponding esters or acids) were described in U.S. Pat. No. 4,876,329. Only the diamine-dianhydride reaction products and imides made from those reaction products were described.
Commonly assigned U.S. Ser. No. 07/584,561 discloses polyimides made from the product of condensation of an aromatic dianhydride (or corresponding acid-ester or polycarboxylic acid) and an aromatic diamine which has at least one trifluoromethyl radical attached to the aromatic ring. It has now been discovered that through the addition of glass, boron, aluminum oxides and mixtures thereof in the form of particulates into the polyimides described above, resins having markedly increased Tg's may be obtained.